Kan tänka mig att det kanske beror på vilket fabrikat det är på displayen. Den nya jag fick är inte likadant (kretskortet är lite annorlunda) som det jag hade...

Min gamla uppvisar heller inget fel, den är ljusstark och jämn och fin (förutom ovanstående beskrivna problem då ).

I følge Marvin :

Wavy Hum-bar, bounce, or Horizontal Roll on the Dot Matrix Display.
The "wavy hum-bar", graphic "bounce, or horizontal roll seen on the dot matrix display's images can be bad DMD power filter capacitors. On WPC-95, these are caps C28, C42 on the audio visual board. On WPC-S and earlier, these are caps C4, C7 on the dot matrix controller board. These original capacitors were 150 mfd 160 volts. This value is somewhat hard to find, but can be replaced with the more common 220 mfd 160 volt electrolytic caps (remember going up in value on electrolytic capacitor's voltage and/or capacitance is Ok, but never go down). If 220 mfd caps are used instead of the 150 mfd, don't get ones that are too large (due to their weight, vibration can crack the capicator's solder pads, essentially removing those new capacitors from the circuit!)

Additionally, if there is still a "wavy hum-bar" or horizontal roll or a display "bounce", try replacing the smaller high voltage filter capacitors. On WPC-S and earlier, these are capacitors C6, C9 and C10 (.1 mfd 500 volts) on the dot matrix controller board. On WPC-95, these are caps C29-C31 (.01 mfd 200 volts). If these caps fail, hum bars or roll can occur. As the game warms up the wave, roll or bounce may change (get better or worse).

http://www.marvin3m.com/wpc/index3.htm#dots

Se på 3k , mye inntresang lesning der.
:-)